JP2005190980A - Fuel cell - Google Patents

Abstract

[Problem] To provide a fuel cell that is capable of satisfactorily supplying gas to an outer electrode of a fuel cell even when a flat fuel cell is used, and having excellent power generation capability.
A gas passage 16 formed inside at least an inner electrode 11, a solid electrolyte 12 formed outside, an outer electrode 13, and the inner electrode 11 are connected to each other and exposed outside the fuel cell 1. A three-dimensional structure current collecting member 20 that allows gas to flow between a plurality of flat fuel cells 1 including the interconnector 14 is disposed, and the opposing fuel cells 1 are 1 to 8 mm in length. A cell stack electrically connected at intervals and housed in a container, wherein at least a part of the outer electrode 13 is exposed, the interconnector 14 of one fuel cell 1 and the current collecting member In the connection space formed between the outer electrode 13 of the other fuel cell 1 connected by 20, the ratio of the current collecting member 20 is 2 to 40% by volume.
[Selection] Figure 2

Description

  The present invention relates to a fuel cell, and more particularly to a fuel cell having a good current collection characteristic of a plurality of electrically connected fuel cells.

  In recent years, various fuel cells in which a stack of fuel cells is accommodated in a storage container have been proposed as next-generation energy.

  FIG. 5 shows a fuel cell 31 of a conventional solid oxide fuel cell. The fuel cell 31 is formed from a cermet on the outer peripheral surface of a cylindrical conductive support tube 34 having a fuel gas passage 32 therein. The fuel electrode 36, the solid electrolyte 38, and the oxygen electrode 40 made of conductive ceramics are sequentially provided. The surface of the conductive support tube 34 that is not covered by the fuel electrode 36, the solid electrolyte 38, and the oxygen electrode 40 is formed. The interconnector 42 is provided.

  The interconnector 42 is formed of a conductive ceramic that is not easily altered by an oxygen-containing gas such as a fuel gas and air. In order to shut off the oxygen-containing gas flowing outside, it must be dense.

  The fuel cell is configured by collecting a plurality of cells having the above-described structure and storing them in a storage container. The fuel cell is configured to flow fuel gas (hydrogen) through the fuel electrode 36 and air (oxygen) through the oxygen electrode 40. Power is generated at 600-1000 ° C.

In the fuel cell constituting the fuel cell described above, generally, the fuel electrode 36 is formed of Ni and ZrO ₂ (YSZ) containing Y ₂ O ₃ , and the solid electrolyte 38 contains Y ₂ O ₃ . is formed from ZrO 2 _(YSZ) for the oxygen electrode 40 is composed of a perovskite-type composite oxide of lanthanum manganate system.

The fuel cells are arranged in a straight line with a certain interval to form a stack. A current collector is inserted between the fuel cells (see Patent Document 1).
JP 2003-317751 A

  Conventionally, metal fibers have been formed into a felt shape and used as a current collector. However, since metal fibers are used, the cross-sectional area of the current collector is reduced and the electrical resistance is increased. .

  And in the fuel cell using such a felt-shaped collector, there existed a problem that electric power generation capability fell greatly with respect to the electric power generation capability per fuel cell by the current collection loss.

  Further, since the felt-shaped current collector is inferior in gas flow, there is a problem that it is difficult to supply gas to the outer electrode connected to the felt-shaped current collector.

  The gas supply will be described in detail. The fuel cells are arranged in a straight line with a certain interval to form a cell stack. If this interval is small, the outer electrode between the fuel cells is Gas is not fully delivered and output characteristics deteriorate.

  On the other hand, if this interval is too large, there is a problem that it becomes difficult to make the fuel cell self-supporting. Further, if the distance is too large, there is a problem that the electrical path of the current collector becomes long and the resistance increases.

  An object of the present invention is to provide a fuel cell capable of ensuring sufficient gas supply to the outer electrodes between fuel cells, reducing current collection loss, and generating high output power. .

  The fuel cell of the present invention includes at least an inner electrode, a gas passage formed inside the inner electrode, a solid electrolyte formed outside the inner electrode, and an outer electrode formed outside the solid electrolyte. A plurality of flat fuel cells connected to the inner electrode and exposed to the outside of the fuel cells are arranged and stored in a storage container at intervals of 1 to 8 mm, A cell stack in which a current collector formed by a three-dimensional structure of a plate-like current collector that allows gas to flow between a plurality of fuel cells is disposed, and the opposed fuel cells are electrically connected to each other A fuel cell comprising at least a part of the outer electrode exposed, and an interconnector of one fuel cell and the other fuel cell connected by the current collector. With the outer electrode Of the connection space formed between the proportion of the current collector is occupied, characterized in that 2 to 40 vol%.

  In the fuel cell of the present invention, the thickness of the plate current collector is preferably 0.2 to 2.0 mm.

  Moreover, as for the fuel battery | cell of this invention, it is desirable for the space | interval of fuel battery cells to be 1.0-5.0 mm.

  In the fuel cell of the present invention, it is desirable that the current collector has a comb-like shape in which a plurality of current collecting pieces are formed at the base.

  In the fuel cell of the present invention, the current collector is preferably a corrugated plate-like current collector.

  In the fuel cell of the present invention, the flat current collector is replaced with a conventionally used felt current collector, and a plate-shaped current collector is used as a current collector. Resistance can be achieved. In addition, the gas flow between the fuel cells can be improved, and the power generation efficiency can be improved. Further, in the space formed by the interconnector of one fuel cell and the outer electrode of the other fuel cell between the fuel cells, the proportion of the current collector is 2 to 40% by volume. By doing so, it is possible to achieve both reduction of current collection loss due to lower resistance of the current collector and supply of gas to the outer electrode, and a fuel cell with excellent power generation performance can be provided.

  In particular, by setting the thickness of the plate current collector to 0.2 mm or more, the electrical resistance of the current collector can be reduced, and the deterioration of the current collector due to the environment to which the current collector is exposed is suppressed. can do. Further, when the thickness of the plate-like current collector is 2 mm or less, elasticity can be imparted to the current collector, so that the connection between the fuel cells can be maintained over a long period of time.

  Further, by setting the distance between the fuel cells to 1 mm or more, the air flowing between the cells becomes sufficient, and stable power generation is possible. Further, when the distance between the fuel cells is 5 mm or less, the resistance of the current flowing through the current collector is small, and stable power generation is possible. Further, if the distance between the fuel cells is 5 mm or less, the heat generated during power generation can be reused for power generation without escaping to the outside, and heat self-sustainment becomes possible.

  In addition, when using a comb-shaped one having a plurality of current collecting pieces formed at the base as the current collector, the current collector and the gas flow path are easily formed in a balanced manner between the fuel cells. can do. In addition, when the current collecting pieces are alternately bent in different directions, the current collectors can be additionally provided with elasticity, so that the fuel cells can be easily and satisfactorily connected to each other over a long period of time.

  In addition, when the corrugated plate-shaped current collector is used, the current collector can be easily formed, the interval between the fuel cells, the volume of the current collector occupied between the fuel cells, etc. Can be changed easily and freely.

  As shown in FIG. 1, the fuel cell shown as 1 as a whole has a cylindrical flat plate cross section and includes a support substrate 10 having an elliptical column shape as a whole. A plurality of fuel gas passages 16 are formed in the support substrate 10 at appropriate intervals, and the fuel cell 1 has a structure in which various members are provided on the support substrate 10.

  As can be understood from the shape shown in FIG. 1, the support substrate 10 includes a flat portion and arc-shaped portions at both ends of the flat portion. Both surfaces of the flat portion are formed substantially parallel to each other, and the fuel electrode layer 11 is provided so as to cover one surface of the flat portion and the arc-shaped portions on both sides, and further, this fuel electrode layer 11 is covered. A dense solid electrolyte layer 12 is laminated, and an oxygen electrode 13 is formed on the solid electrolyte layer 12 from one surface of the flat portion to the arc-shaped portions on both sides so as to face the fuel electrode layer 11. Are stacked. In addition, an interconnector 14 is formed on the other surface of the flat portion where the fuel electrode layer 11 and the solid electrode layer 12 are not laminated via a bonding layer 15 as necessary. As is clear from FIG. 1, the fuel electrode layer 11 and the solid electrolyte layer 12 extend to both sides of the interconnector 14 and are configured so that the surface of the support substrate 10 is not exposed to the outside.

  In the fuel cell having the above structure, the portion of the fuel electrode layer 11 facing the oxygen electrode 13 operates as a fuel electrode to generate electric power. That is, an oxygen-containing gas such as air is allowed to flow outside the oxygen electrode 13 and a fuel gas (hydrogen) is allowed to flow through the gas passage 16 in the support substrate 10 to be heated to a predetermined operating temperature. Electricity is generated by generating an electrode reaction of the formula (1) and generating an electrode reaction of the following formula (2) in the portion that becomes the fuel electrode of the fuel electrode layer 11.

Oxygen electrode: 1 / 2O ₂ + 2e ⁻ → O ²⁻ (solid electrolyte) (1)
Fuel electrode: O ²⁻ (solid electrolyte) + H ₂ → H ₂ O + 2e ⁻ (2)
The current generated by such power generation is collected via the interconnector 14 attached to the support substrate 10.

  In the fuel cell of the present invention having the above-described structure, the support substrate 10 is gas permeable so as to allow the fuel gas to permeate to the fuel electrode, and to collect current through the interconnector. Although it is required to be conductive, the support substrate 10 is composed of an iron group metal component and a specific rare earth oxide in order to satisfy such a requirement and at the same time avoid problems caused by simultaneous firing.

  The iron group metal component is for imparting conductivity to the support substrate 10 and may be an iron group metal alone, or an iron group metal oxide, an iron group metal alloy or an alloy oxide. May be. The iron group metals include iron, nickel, and cobalt. In the present invention, any of them can be used, but Ni and / or NiO is changed to iron group because it is inexpensive and stable in fuel gas. It is preferable to contain as a component.

The rare earth oxide component is used for approximating the thermal expansion coefficient of the support substrate 10 to the stabilized zirconia forming the solid electrolyte layer 12, maintaining a high conductivity and maintaining the solid electrolyte layer. In order to prevent diffusion to 12 etc., oxides Y ₂ O ₃ and Yb ₂ O ₃ containing rare earth elements are used in combination with the iron group component.

In the present invention, the iron group component described above is contained in the support substrate 10 in an amount of 35 to 65% by volume, particularly in that the thermal expansion coefficient of the support substrate 10 is approximated to stabilized zirconia. Is preferably contained in the support substrate 10 in an amount of 35 to 65% by volume. The support substrate 10 composed of the iron group metal component and the rare earth oxide as described above has a fuel gas permeability. In general, it is preferable that the open porosity is 30% or more, particularly 35 to 50%. Further, the conductivity of the support substrate 10 is preferably 300 S / cm or more, and particularly preferably 440 S / cm or more.

  The length of the flat portion of the support substrate 10 is usually 15 to 35 mm, the length of the arc-shaped portion (arc length) is about 3 to 8 mm, and the thickness of the support substrate 10 is (both surfaces of the flat portion). Is preferably about 2.5 to 5 mm.

In the present invention, the fuel electrode layer 11 causes the electrode reaction of the above-described formula (2), and is formed of a known porous conductive ceramic. For example, it is formed from ZrO ₂ in which a rare earth element is dissolved, and Ni and / or NiO. As ZrO ₂ (stabilized zirconia) in which the rare earth element is dissolved, the same one used for forming the solid electrolyte layer 12 described below is preferably used.

  Further, in the example of FIG. 1, the fuel electrode layer 11 extends to both sides of the interconnector 14, but the fuel electrode only has to be formed at a position facing the oxygen electrode 13, For example, the fuel electrode layer 11 may be formed only on the flat portion on the side where the oxygen electrode 13 is provided.

The solid electrolyte layer 12 provided on the fuel electrode layer 11 is generally formed of a dense ceramic called ZrO ₂ (usually stabilized zirconia) in which 3 to 15 mol% of a rare earth element is dissolved. . Examples of rare earth elements include Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, but they are inexpensive. From the point, Y and Yb are desirable.

The oxygen electrode 13 is formed of a conductive ceramic made of a so-called ABO ₃ type perovskite oxide. As such a perovskite oxide, at least one of transition metal perovskite oxides, particularly LaMnO ₃ oxides, LaFeO ₃ oxides, and LaCoO ₃ oxides having La at the A site is preferable. LaFeO ₃ -based oxides are particularly suitable because they have high electrical conductivity at an operating temperature of about 1000 ° C. In the perovskite oxide, Sr and the like may exist together with La at the A site, and Co and Mn may exist together with Fe at the B site.

The interconnector 14 provided on the support substrate 10 is generally made of a lanthanum chromite perovskite oxide (LaCrO ₃ oxide). Further, in order to prevent leakage of the fuel gas passing through the inside of the support substrate 10 and the oxygen-containing gas passing through the outside of the support substrate 10, such conductive ceramics must be dense, for example 93% or more, particularly 95%. It is preferable to have the above relative density.

  A P-type semiconductor 17 is preferably provided on the outer surface (upper surface) of the interconnector 14. A conductive current collector 20 is connected to the interconnector 14. However, if the current collector 20 is directly connected to the interconnector 14, a potential drop increases due to non-ohmic contact, and current collecting performance is improved. It will decline. As such a P-type semiconductor 17, a transition metal perovskite oxide can be exemplified.

  The fuel battery cell having the above structure is manufactured as follows.

First, a slurry is prepared by mixing an iron group metal such as Ni or its oxide powder, a rare earth oxide powder such as Y ₂ O ₃ , an organic binder, and a solvent, and extrusion using this slurry. A support substrate molded body is produced by molding and dried.

  Next, a fuel electrode layer forming material (Ni or NiO powder and stabilized zirconia powder), an organic binder, and a solvent are mixed to prepare a slurry, and a sheet for the fuel electrode layer is prepared using this slurry. Further, instead of producing a sheet for the fuel electrode layer, a paste in which the fuel electrode forming material is dispersed in a solvent is applied to a predetermined position of the formed support substrate and dried, and then the fuel electrode layer is formed. A coating layer may be formed.

Furthermore, a stabilized zirconia powder, an organic binder, and a solvent are mixed to prepare a slurry, and a solid electrolyte layer sheet is prepared using this slurry.

  The support substrate molded body, the fuel electrode sheet, and the solid electrolyte layer sheet formed as described above are laminated so as to have a layer structure as shown in FIG. 1, for example, and dried. In this case, when the coating layer for the fuel electrode layer is formed on the surface of the support substrate molded body, only the solid electrolyte layer sheet may be laminated on the support substrate molded body and dried.

Thereafter, the interconnector material (e.g., LaCrO ₃ based oxide powder), an organic binder and a solvent were mixed to prepare a slurry, to produce the interconnector sheet.

  This interconnector sheet is further laminated at a predetermined position of the laminate obtained above to produce a firing laminate.

Next, the above-mentioned fired laminate is subjected to binder removal treatment, and co-fired at 1300 to 1600 ° C. in an oxygen-containing atmosphere, and an oxygen electrode forming material (for example, LaFeO ₃₎ is placed at a predetermined position of the obtained sintered body. A paste containing a system oxide powder) and a solvent, and if necessary, a paste containing a P-type semiconductor forming material (for example, LaFeO ₃ system oxide powder) and a solvent by dipping or the like, at 1000 to 1300 ° C. I baked it.

  In the case where Ni alone is used to form the support substrate 10 and the fuel electrode layer 11, Ni is oxidized to NiO by firing in an oxygen-containing atmosphere. , Ni can be returned. Further, since it is exposed to a reducing atmosphere during power generation, it is also reduced to Ni at this time.

  A high voltage can be obtained by arranging the fuel cells in series as shown in FIG. 2 to form a stack structure. The fuel cell is installed in a manifold (not shown) made of a refractory metal or ceramic. The fuel cells are connected to the manifold by a fixing material (not shown) made of glass or cement for sealing and fixing. A current collector 20 for current collection is installed between the fuel cells. The current collector 20 is electrically connected to the oxygen electrode 13 and the P-type semiconductor 17 of the fuel cell.

  According to the example shown here, since the outer electrode of the fuel cell is the oxygen electrode layer 13, the air necessary for power generation is supplied to the outside of the fuel cell, and in particular, the gap between the fuel cells. Need to pass through.

  The use of a plate-like current collector as the current collector 20 disposed between the fuel cells is important from the viewpoint of reducing the electrical resistance of the current collector. As in the example shown here, the current collector When 20 is exposed to an oxidizing atmosphere, it is particularly important to use a plate-like current collector having a small surface area as the current collector 20.

  In addition, the distance between the fuel cells is preferably 1 mm or more, and more preferably 2 mm or more, from the viewpoint of favorably flowing gas to the outer electrode.

  Further, from the viewpoint of reducing the size of the fuel cell and improving the power generation efficiency, it is desirable to make it 5 mm or less, and further, by making it 4 mm or less, a fuel cell that is compact and has high power generation efficiency and excellent thermal self-sustainability. Can be provided.

  Moreover, the electrical resistance of the electrical power collector 20 can be made small, and an electrical power collection loss can be made small by making the ratio which a collector occupies in the space between fuel cell cells into 2 volume% or more. Moreover, when the ratio which the electrical power collector 20 accounts is 5 volume% or more, especially 10 volume% or more, a current collection loss can further be reduced and the electric power generation capability of a fuel cell can be improved.

  In addition, by setting the ratio of the current collector 20 to 40% by volume or less, it is possible to secure a gas supply channel to the outer electrode, and the power generation of the fuel cell is not hindered. In particular, when the proportion of the current collector 20 is 30% by volume or less, reduction of current collection loss and maintenance of gas supply can be achieved at a high level at the same time.

  The plate-like current collector used as the current collector 20 can have various forms as long as the supply of gas to the outer electrode is not hindered. For example, a comb-shaped current collector as shown in FIG. Alternatively, a plate-like current collector having irregularities on the main surface as shown in FIG. 4 is preferably used.

  The current collector 20 and the outer electrode are preferably connected so that the connection portions and the gas flow portions are alternately formed at a predetermined interval.

  Further, particularly in the structure where the fuel cell stack is used, the portion where the gas supply is difficult is smaller than the other portions, and the proportion of the current collector 20 is reduced, so that the amount of gas flow is increased. It is desirable to connect the battery cell and the current collector 20.

  As such a current collector, a heat resistant metal containing Fe, Cr or the like is preferably used.

  In addition, it cannot be overemphasized that the plate-shaped electrical power collector of not only the above-mentioned example but various forms may be used for the fuel cell of this invention.

NiO powder or Ni powder having an average particle size of 0.5 μm and Y ₂ O ₃ powder (average particle size is 0.8 to 1.0 μm) have a volume ratio after firing, and NiO is 65 in terms of Ni after firing. next _vol%, Y 2 _{O 3} were mixed so that 35% by volume.

  A support substrate slurry formed by mixing the above-mentioned mixed powder with a pore-forming agent, an organic binder (polyvinyl alcohol) and water (solvent) is extruded into a rectangular parallelepiped shape, and a flat support substrate molded body is obtained. Prepared and dried. The obtained molded body was debindered and calcined at 1000 ° C. in the air.

Next, for forming a fuel electrode layer using a slurry obtained by mixing ZrO ₂ (YSZ) powder containing 8 mol% Y ₂ O ₃ , NiO powder, organic binder (acrylic resin), and solvent (toluene). A sheet was prepared, and a sheet for a solid electrolyte layer was prepared using a slurry in which the YSZ powder, an organic binder (acrylic resin), and a solvent made of toluene were mixed, and these sheets were laminated.

  The laminated sheet was wound around the support substrate molded body so that both ends thereof were separated from each other with a predetermined interval (see FIG. 1), and dried.

On the other hand, an interconnector sheet was prepared using a slurry in which an LaCrO ₃ oxide powder having an average particle diameter of 2 μm, an organic binder (acrylic resin), and a solvent (toluene) was mixed. A laminated sheet for sintering was prepared by laminating on the exposed portion of the support substrate molded body in the sheet, and comprising a support substrate molded body, a fuel electrode layer sheet, and a solid electrolyte layer sheet.

  Next, the laminated sheet for sintering was subjected to binder removal treatment and co-fired at 1500 ° C. in the atmosphere.

The obtained sintered body was immersed in a paste made of La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O ₃ powder having an average particle diameter of 2 μm and a solvent (normal paraffin), and sintered. A coating layer for oxygen electrode is provided on the surface of the solid electrolyte layer formed on the body, and at the same time, the paste is applied to the outer surface of the interconnector formed on the sintered body, and a coating layer for P-type semiconductor is provided, Furthermore, it baked at 1150 degreeC and produced the fuel battery cell as shown in FIG.

  After sintering by the above method, a fuel cell having an electrode area of 95.0 × 24.5 mm, a cell length of 130 mm, a width of 25 mm, and a thickness of 3.2 mm was produced. In addition, the six holes produced during extrusion molding had a diameter of 1.6 mm after sintering so that fuel would flow inside the cell.

  Then, the size of the comb-shaped plate-like current collecting member shown in FIG. 3 is changed between these fuel cells, as shown in Table 1, and is sandwiched between a pair of fuel cells and a current collector. A unit was prepared and a power generation test was performed at 750 ° C.

  The power generation efficiency when power was generated stably at 750 ° C. was calculated by dividing the obtained output by the energy of hydrogen using the output.

  In addition, it heat-processed by interposing the electrically conductive paste containing Ag powder between a collector and a fuel battery cell, and the collector and the fuel battery cell were joined.

In addition, the test using the current collection member which consists of Ni felt conventionally used as a comparative example was also done.

  As is apparent from Table 1, the sample No. using a conventional felt-shaped current collector as the current collector which is outside the scope of the present invention. In 13, the output is 11.8 W, clearly showing that the output is low.

  On the other hand, using a comb-like plate-like current collecting member as the current collector, the sample volume of the sample No. In Nos. 2 to 7 and 9 to 12, sample Nos. Using conventional felt-shaped current collectors were used. Compared with 13, an output of 30.1 W or higher and a power generation efficiency of 41.7% or higher were obtained, and a significantly higher output and power generation efficiency were achieved.

  Although a comb-like plate-like current collecting member is used as the current collector, the sample volume of the current collector occupied by the current collector between the fuel cells is less than 2%. 1 and Sample No. in which the volume fraction occupied by the current collector between the fuel cells exceeds 40% by volume. In sample No. 8, sample no. Although higher output and power generation efficiency than 13 can be obtained, both output and power generation efficiency are lower than those of the fuel cell of the present invention.

It is a perspective view which shows one form of the fuel cell used for the fuel cell of this invention. It is sectional drawing which shows the state which connected the fuel cell using the plate-shaped current collection member of the comb-tooth shape in which the several current collection piece was formed in the one end part of a base. FIG. 2 is a side view of a plate-like current collector, showing a state in which fuel cells are connected to each other using a comb-like plate-like current collector member in which a plurality of current collecting pieces are formed at one end of a base portion. (A) is a top view which shows the plate-shaped uneven | corrugated plate-shaped current collection member from which a main surface becomes corrugated, (b) is sectional drawing which shows a plate-shaped uneven | corrugated plate-shaped current collection member. . It is a cross-sectional view showing a typical structure of a conventional fuel cell.

Explanation of symbols

1: Fuel cell 10: Electrode support substrate 11: Fuel electrode 12: Solid electrolyte 13: Oxygen electrode 14: Interconnector 17: P-type semiconductor 20: Current collector 20a: Current collecting piece 20b of comb-shaped current collector: Comb Tooth-shaped current collector base 20c: Plate current collector 20d: Plate current collector 30: Fitting

Claims (5)

At least an inner electrode, a gas passage formed inside the inner electrode, a solid electrolyte formed outside the inner electrode, an outer electrode formed outside the solid electrolyte, and a fuel connected to the inner electrode, A plurality of flat fuel cells each having an interconnector exposed outside the battery cells are arranged and stored in a storage container at an interval of 1 to 8 mm, and the plurality of fuel cells are interposed between the plurality of fuel cells. A fuel cell in which a current collector formed by a three-dimensional structure of a plate-shaped current collector through which gas can flow is disposed, and a cell stack formed by electrically connecting the opposed fuel cells is housed And at least a part of the outer electrode is exposed and formed between the interconnector of one fuel cell and the outer electrode of the other fuel cell connected by the current collector. Connection Of between the fuel cell rate which the current collector is occupied, characterized in that 2 to 40 vol%. The fuel cell according to claim 1, wherein the plate-like current collector has a thickness of 0.2 to 2.0 mm. The fuel cell according to claim 1 or 2, wherein an interval between the fuel cells is 1.0 to 5.0 mm. The fuel cell according to any one of claims 1 to 3, wherein the current collector has a comb shape in which a plurality of current collecting pieces are formed at a base portion. The fuel cell according to any one of claims 1 to 3, wherein the current collector is a corrugated plate-like current collector.

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